Hydroprocessing Catalysts and Methods for Making Thereof

ABSTRACT

A method to upgrade heavy oil feedstock using an ebullated bed reactor and a novel catalyst system is provided. The ebullated bed reactor system includes two different catalyst with different characteristics: an expanded catalyst zone containing particulate catalyst having a particle size of greater than 0.65 mm; and a slurry catalyst having an average particle size ranging from 1 to 300 μm. The slurry catalyst is provided to the ebullated bed system containing the heavy oil feedstock, and entrained in the upflowing hydrocarbon liquid passing through the ebullated bed reaction zone. The slurry catalyst reduces the formation of sediment and coke precursors in the ebullating bed reactor system. The slurry catalyst is prepared from rework materials, which form a slurry catalyst in-situ upon mixing with the heavy oil feedstock.

RELATED APPLICATIONS

This application claims benefit under 35 USC 119 of U.S. ProvisionalPatent Application Nos. 61/424,804 with a filing date of Dec. 20, 2010;61/428,599 with a filing date of Dec. 30, 2010; and 61/562,850 with afiling date of Nov. 22, 2011. This application claims priority to andbenefits from the foregoing, the disclosures of which are incorporatedherein by reference.

TECHNICAL FIELD

The invention relates generally to catalysts for use in the conversionof heavy oils and residua and methods for making thereof.

BACKGROUND OF THE INVENTION

Heavy oil is particularly difficult to upgrade in refinery operations.Metals contained in the oil tend to rapidly deactivate catalysts withwhich they come in contact during the upgrading process. Heavy oilsoften contain high concentrations of sulfur and nitrogen, which aredifficult to remove to the extent necessary for further processing ofthe upgraded products from heavy oil processing. The aromatic characterof many heavy oils tends to contribute to instability of the upgradedproducts. While heating the heavy oils, even in the presence of highpressure hydrogen, components of the heavy oil thermally crack to yieldfree radicals, which quickly combine to make sediment and cokeprecursors unless they are quickly suppressed by active catalysis.Furthermore, during catalysis, high molecular weight coke precursorsdeposit on catalysts and quickly reduce catalytic activity.

Rapid deactivation of catalysts used in heavy oil processing serviceoften requires frequent replacement of catalysts in the heavy oilprocessing systems. Several systems have been proposed for replacing aportion of the catalyst at regular intervals during the heavy oilprocessing, without requiring that the system be shut down for catalystreplacement. In an ebullated bed heavy oil processing system, thecatalyst is maintained in a fluidized state within the reaction zone. Atperiodic intervals, a portion of the fluidized bed of catalyst, alongwith a small portion of fluidizing liquid, is removed from the system. Acomparable amount of catalyst is added to the system, to maintain aconstant quantity of catalyst in the system at any one time.

An ebullated bed processing system for use in heavy oil processing has afairly low catalyst/oil ratio within the reaction zone. It is desirableto increase the catalyst/oil ratio to improve the overall effectivenessof the system, without requiring significant modifications to thesystem. U.S. Pat. Nos. 7,815,870; 7,449,103; 8,024,232; 7,618,530, andUS Patent Publication Nos. 2011/0226667 and 2009/0310435 discloseebullating bed hydroprocessing systems wherein the catalyst systemcomprises both a porous supported catalyst and a “colloidal” catalystfor the upgrade of heavy oil feedstock. The single-metallic colloidalcatalyst employed is synthesized in-situ upon mixing with the heavy oilfeedstock under sufficient conditions for sulfidation to occur; thustight control of the catalyst properties is difficult. A processemploying an in-situ synthesized catalyst requires carefully controlledsteps for the dilution of the catalyst precursor and mixing with a heavyoil feedstock for sulfidation to take place.

There is still a need for an improved reaction feed system with improvedproperties and performance for heavy oil conversion processes.

SUMMARY

In one aspect, the invention relates to an ebullated bed heavy oilprocessing system for converting heavy oil. The process comprises:passing a reaction mixture comprising heavy oil feedstock in thepresence of hydrogen and a slurry catalyst to an ebullated bed reactionzone, the slurry catalyst having an average particle size ranging from 1to 300 μm; upflowing the mixture comprising the heavy oil and slurrycatalyst and hydrogen through an expanded catalyst zone in the ebullatedbed reaction zone and fluidizing a particulate catalyst in the expandedcatalyst zone to produce an upgraded heavy oil, the particulate catalysthaving a particle size of greater than 0.65 mm ( 1/40 in.); and passingthe upgraded heavy oil and at least a portion of the slurry catalyst toa disengagement zone of the ebullated bed reaction zone.

In another aspect, the invention relates to a dual catalyst system foruse in an ebullated bed system, the feed system comprising a slurrycatalyst with an average particle size ranging from 1 to 300 μm, and aparticulate catalyst having a particle size of greater than 0.65 mm (1/40 in.) for use in the expanded catalyst zone of the ebullated system,wherein the slurry catalyst is injected into the ebullated bed systemforming a mixture with the heavy feedstock.

In yet another aspect, the invention relates to a process for convertingheavy oil using an ebullated bed system, the process comprising: passinga reaction mixture comprising a heavy oil feedstock and a slurrycatalyst in the presence of hydrogen to a hydroconversion reaction zone,forming a reaction mixture; upflowing the reaction mixture through anexpanded catalyst zone employing a particulate catalyst in thehydroconversion reaction zone and fluidizing the particulate catalyst inthe expanded catalyst zone to produce an upgraded heavy oil; wherein theslurry catalyst has an average particle size ranging from 1 to 300 μm.

In one other aspect, the invention relates to an ebullating bed reactionsystem for heavy oil upgrade, comprising: an expanded catalyst zonecomprising a particulate catalyst having a particle size of greater than0.65 mm and a slurry catalyst having an average particle size of atleast 1 μm; a plenum chamber below the expanded catalyst zone containingslurry catalyst in the absence of particulate catalyst; and adisengagement zone above the expanded catalyst zone, at least a portionof which contains slurry catalyst in the absence of the particulatecatalyst. In one embodiment, the reaction system further comprises arecirculation conduit for recirculating at least a portion of ahydrocarbonaceous liquid in the disengagement zone to the plenumchamber.

In yet another aspect, the invention relates to a method of upgrading apre-existing ebullated bed hydroprocessing system in order to reduceformation of coke and/or sediment, comprising: (a) operating apre-existing ebullated bed hydroprocessing system comprising one or moreebullated bed reactors, each of which comprises a liquid hydrocarbonphase, a solid phase comprised of an expanded bed of particulatecatalyst, a gaseous phase comprising hydrogen gas, and catalyst freezones above and below the expanded bed of the particulate catalyst; (b)providing a sulfided slurry catalyst having an average particle sizeranging from 1 to 300 μm; (c) introducing a heavy oil feedstock and theslurry catalyst into at least one ebullated bed reactor, wherein theslurry catalyst is dispersed throughout the liquid hydrocarbon phase ofthe pre-existing ebullated bed hydroprocessing system; and (d) operatingthe upgraded ebullated bed hydroprocessing system to form ahydroprocessed material, wherein the introduction of the slurry catalystreduces formation of coke or sediment in the upgraded ebullated bedhydroprocessing system compared to the pre-existing ebullated bedhydroprocessing system.

In another aspect, the invention relates to a method of hydroprocessinga heavy oil feedstock. The method comprises: (a) introducing to anebullated reactor a heavy oil feedstock feed and a slurry catalysthaving an average particle size ranging from 1 to 300 μm; heating ormaintaining the heavy oil feedstock at a hydrocracking temperature toyield an upgraded material; wherein the ebullated bed reactorcomprising: a liquid phase comprised of hydrocarbons and the slurrycatalyst; a solid phase comprised of a particulate catalyst within anexpanded catalyst bed; a gaseous phase comprised of hydrogen; and zonesabove and below the expanded catalyst bed that are devoid of theparticulate catalyst, and wherein the slurry catalyst being dispersedthroughout the liquid phase, including the particulate catalyst freezones, and catalyzing reactions between the hydrogen and free radicalsformed from the heavy oil feedstock throughout the liquid phase,including the particulate catalyst free zones, to yield an upgradedmaterial while reducing or eliminating formation of coke precursors andsediment within the ebullated bed reactor compared to an ebullated bedreactor in the absence of the slurry catalyst.

In one aspect, the invention relates to an ebullated bed hydroprocessingsystem. The system comprises an ebullated bed reactor which is comprisedof: an expanded catalyst bed comprising a particulate catalyst; an upperregion above the expanded catalyst bed that is devoid of the particulatecatalyst; a lower region below the expanded catalyst bed that is devoidof the particulate catalyst; a liquid hydrocarbon phase comprised of aheavy oil feedstock within the expanded catalyst bed, the upper region,and the lower region; a slurry catalyst having an average particle sizeranging from 1 to 300 μm dispersed throughout the liquid hydrocarbonphase; and a gaseous phase comprised of hydrogen gas dispersed in theliquid hydrocarbon phase.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of the ebullated bed reaction zone,including the provision of slurry catalyst to the reaction zone.

DETAILED DESCRIPTION

The following terms will be used throughout the specification and willhave the following meanings unless otherwise indicated.

The term “hydrocarbon” refers broadly to any compound containing bothhydrogen and carbon and includes liquid, vapor and combined liquid/vaporstreams containing greater than about 80 weight percent hydrogen andcarbon, calculated as the elements.

“Hydrocarbonaceous liquid” refers to a liquid phase hydrocarbon.

“Sediment” refers to filterable insoluble material that occurs in heavyoil. In general, the amount of sediment tends to increase as the boilingweight of the heavy oil increases. Sediment is produced in the heavy oilat high temperatures, often from thermal decomposition of molecules inthe heavy oil. There are a number of tests for sediment. The Shell HotFiltration test is one example. Although sediment may be quitetroublesome for downstream processing, it is generally in lowconcentrations (e.g. less than 1-2 wt. % in the heaviest vacuum residuumproduct from the ebullated bed reaction zone).

“Unsupported catalyst” may be used interchangeably with “bulk catalyst”or “self-supported catalyst,” referring to catalysts that are not of theconventional catalyst form, having a preformed, shaped catalyst supportwhich is then loaded with metals via impregnation or deposition methods.In one embodiment, the unsupported catalyst is formed throughprecipitation. In another embodiment, the unsupported catalyst hasdiluent (or binder) incorporated into the catalyst composition. In yetanother embodiment, the unsupported catalyst is formed from metalcompounds and without any binder. In one embodiment, the unsupportedcatalyst is a dispersing-type catalyst (“slurry catalyst”) type withdispersed particles in a liquid mixture (e.g., hydrocarbon oil).

“Supported catalyst” refers to a catalyst that is affixed onto ashaped/preformed solid (“a carrier” or a support) comprising any ofalumina, silica, magnesia, titania, aluminosilicates, aluminophosphates,carbon, porous metals, and combinations thereof. The catalyst is affixedonto the support via methods including but not limited to impregnationor deposition.

“Rework” “may be used interchangeably with “rework materials” or“catalyst fines,” referring to catalyst products, scrap pieces, fines,rejected materials obtained from the process of making any of sulfidedcatalyst, unsulfided supported catalyst, and unsulfided self-supportedcatalyst, reduced in size to fines or powdered materials containing oneor more catalytic materials. The catalyst fines can be generated from acatalyst product, or from rejected materials/scrap pieces containingcatalytic materials generated in the process of making the catalystproduct. In one embodiment, the rework is from the process of makingsupported catalyst precursor, in the form of final products, catalystfines, broken pieces, scrap pieces and the like, and before the shapedcatalyst precursor is sulfided. In one embodiment, the rework is in theform of final products, waste, fines, etc., generated from the processof forming/shaping a bulk catalyst precursor and before the sulfidationstep. In another embodiment, the rework is in the form of finesgenerated from grinding any of supported catalyst products, unsupportedcatalyst products, scrap pieces, fines, and combinations thereof,generated in a process to make a supported catalyst or an unsupportedcatalyst.

“Catalyst precursor” refers to a compound containing one or morecatalytically active metals, from which compound a slurry catalyst isformed, and which compound may be catalytically active as ahydroprocessing catalyst, an example is a water-based catalyst prior tothe transformation step with a hydrocarbon diluent, or an oxide orhydroxide catalyst precursor prior to the sulfidation step.

“Slurry catalyst” refers to a suspension of catalyst and/or catalystprecursor solid particles in a liquid carrier such as hydrocarbondiluent or heavy oil, which solid particles have an average particlesize of greater than 1 μm. In the process, the slurry catalyst issupplied to the reaction zone, or to liquids flowing to the reactionzone, as a slurry in a hydrocarbonaceous liquid or other suitable liquidcarrier. In one embodiment, the slurry catalyst is a “powdered catalyst”prepared from rework material.

“Double salt metal precursor” refers to a metal precursor having atleast two different metal cations in the crystal lattice, with at leastone Primary metal cation and at least one Promoter metal cation, e.g.,ammonium nickel molybdate (formed from ammonium molybdate with nickelsulfate).

“Heavy feedstock” and “heavy oil feedstock” and “heavy oil” are usedinterchangeably to refer to a fossil fuel feedstock and/or fractionthereof including, but not limited to, one or more of heavy crude oil, areduced crude oil, petroleum residuum, atmospheric tower bottoms, vacuumtower bottoms, tar sands bitumen, shale oil, liquefied coal, coal tar,or reclaimed oil. Heavy feedstocks typically contain contaminants, suchas carbon residue, sulfur, and metals, which are known to deactivate thecatalysts used to upgrade the heavy feedstocks to more valuable productssuch as transportation fuels and lubricating oils. An exemplaryatmospheric tower bottoms has a boiling point of at least 343° C. (650°F.); an exemplary vacuum tower bottoms has a boiling point of at least524° C. (975° F.). Heavy oil within the hydroconversion reaction zonewill contain some amount of converted or upgraded products, the amountdepending on the extent of reaction to which the heavy oil has beensubjected. In one embodiment, properties of heavy oil feedstock include,but are not limited to a sulfur content of at least 2 wt. %, a metal(Ni/V/Fe) content of greater than 10 ppm by weight, a density of morethan 0.93 g/cm³, (or more than 0.97 g/cm³, or ranging from 0.97 to 1.13g/cm³). Exemplary heavy oil feeds include Athabasca bitumen (Canada),which typically has at least 50% by volume vacuum reside, a Boscan(Venezuela) heavy oil feed, which may contain at least 64% by volumevacuum residue, a Borealis Canadian bitumen, which may contain about 5%sulfur and 19% of asphaltenes.

“Treatment,” “treated,” “upgrade”, “upgrading” and “upgraded”, when usedin conjunction with a heavy oil feedstock, describes a heavy oilfeedstock that is being or has been subjected to hydroprocessing, or aresulting material or crude product, having a reduction in the molecularweight of the heavy oil feedstock, a reduction in the boiling pointrange from the heavy oil feedstock, a reduction in the concentration ofasphaltenes, a reduction in the concentration of hydrocarbon freeradicals, and/or a reduction in the quantity of impurities, such assulfur, nitrogen, oxygen, halides, and metals.

The upgrade or treatment of heavy oil feeds is generally referred hereinas “hydroprocessing” (hydrocracking, or hydroconversion).Hydroprocessing is meant as any process that is carried out in thepresence of hydrogen, including, but not limited to, hydroconversion,hydrocracking, hydrogenation, hydrotreating, hydrodesulfurization,hydrodenitrogenation, hydrodemetallation, hydrodearomatization,hydroisomerization, hydrodewaxing and hydrocracking including selectivehydrocracking. The products of hydroprocessing may show improvedviscosities, viscosity indices, saturates content, low temperatureproperties, volatilities and depolarization, etc.

SCF/BBL (or scf/bbl) refers to a unit of standard cubic foot of gas (N₂,H₂, etc.) at 60° F. and 1 atmosphere pressure per barrel of hydrocarbonfeed, or slurry catalyst, depending on where the unit is used.

The Periodic Table referred to herein is the Table approved by IUPAC andthe U.S. National Bureau of Standards, an example is the Periodic Tableof the Elements by Los Alamos National Laboratory's Chemistry Divisionof October 2001.

“Metal” refers to metallic elements in their elemental, compound, orionic form. “Metal precursor” refers to the metal compound feed to theprocess. The term “metal” or “metal precursor” in the singular form isnot limited to a single metal or metal precursor, e.g., a Group VIB or aPromoter metal, but also includes the plural references for mixtures ofmetals. “In the solute state” means that the metal component is in aprotic liquid form.

“Group VIB metal” refers to chromium, molybdenum, tungsten, andcombinations thereof in their elemental, compound, or ionic form.

“Group VIII metal” refers iron, cobalt, nickel, ruthenium, rhenium,palladium, osmium, iridium, platinum, and combinations thereof.

“d” block elements refer to elements of the Periodic Table wherein the dsublevel of the atom is being filled. Examples include Sc, Ti, V, Cr,Mn, Fe, Co, Ni, Cu, and Zn.

“Primary metal” refers to a metal in its elemental, compound, or ionicform selected from any of Group VIB (IUPAC nomenclature Group 6), GroupVIII metals (IUPAC nomenclature Group s 8-10), Group IIB metals, “d”block elements, and combinations thereof which, in its sulfided form,functions as a catalyst in a hydroprocessing process. The Primary metalis present in a catalyst in a larger amount than other metals.

“Promoter metal” refers to a metal in its elemental, compound, or ionicform selected from any of Group IVB (IUPAC nomenclature Group 4), GroupVIB (IUPAC nomenclature Group 6), Group VIII, Group IIB (IUPACnomenclature Group 12), and combinations thereof, added to increase thecatalytic activity of the Primary metal. Promoter metal is present in asmaller amount than the Primary metal, in a range from 1-50 wt. %(Promoter metal to Primary metal).

“Free of Promoter metal” or “substantially free of Promoter metal” meansthat in making the catalyst, no Promoter metal in their elemental,compound, or ionic form, is added. Traces of Promoter metals can bepresent, in an amount of less than 1% of the Primary metal (wt. %).

1000° F.+ conversion rate refers to the conversion of a heavy oilfeedstock having a boiling point of greater than 1000° F.+ to less than1000° F. (538.° C.) boiling point materials in a hydroconversionprocess, computed as: 100%*(vol % boiling above 1000° F. materials infeed−vol % boiling above 1000° F. materials in products)/vol % boilingabove 1000° F. materials in feed). 1000° F.+ conversion rate sometimescan also be computed based on wt. %, such as: 100%*(wt. % boiling above1000° F. materials in feed−wt. % boiling above 1000° F. materials inproducts)/wt. % boiling above 1000° F. materials in feed).

Pore porosity and pore size distribution can be measured using mercuryintrusion porosimetry, designed as ASTM standard method D 4284, ormeasured using the nitrogen adsorption method.

Particle size and particle size distribution in one embodiment aremeasured using laser diffraction analysis technique, employingcommercially available laser particle size analyzers known in the art.

The present system and process for upgrading heavy oil is suitable forhydroprocessing a petroleum based material, such as a heavy oil; liquidsprepared from coal, tar sands, shale oil; the product from a hydrocarbonsynthesis process such as Fischer Tropsch; or combinations thereof. Thesystem includes two different catalysts. In one embodiment of the dualcatalyst system, the first catalyst is a supported catalystcharacterized by catalyst particulates (“extrudates” or “pellets”)comprising a metal or metal compound having hydrogenation activity andsupported on a support, having particle sizes within a range to fluidizein an expanded catalyst bed within the system. As used herein, thesupported catalyst is termed a “particulate catalyst”. The secondcatalyst is a slurry catalyst. The particle size of the slurry catalystis within a range to permit the catalyst to be transported upwardthrough an expanded catalyst bed within the hydroconversion reactionzone by fluids flowing upward through the zone. The slurry catalyst ischaracterized as having a smaller particle size relative to that of theparticulate catalyst. Other catalysts may be employed as needed toachieve objectives that are specific to an individual operation of thesystem.

The hydroconversion reaction process involves the conversion of heavyoil by contacting the heavy oil with hydrogen in the presence of thedual catalyst system. Conversion reactions include one or more of:molecular weight reduction by catalytic or thermal cracking; heteroatomor metal removal; asphaltene or carbon residue reduction; olefin oraromatic saturation; and skeletal or double bond isomerization.Reactions of this type are generally conducted at elevated temperaturesand at supra-atmospheric pressures in combination with hydrogen and inthe presence of a catalyst.

Ebullated Bed Heavy Oil Processing System: In one embodiment, thehydroconversion reaction zone is an ebullated bed heavy oil processingsystem, which typically includes at least one ebullated bed reactionzone, with each zone generally contained within a single reactor vessel.In one embodiment, the ebullated bed heavy oil processing systemcomprises multiple reaction zones, each in fluid contact via at leastone fluid stream with at least one other reaction zone in the system.The ebullated bed reaction zone includes an expanded catalyst zonecomprising particulate catalyst, which is maintained by upflowing heavyoil and hydrogen through the bed at a velocity sufficient to expand orfluidize the particulate catalyst in the bed, but modulated such thatthe particulate catalyst are not carried out of the reactor vessel bythe upflowing fluids. The ebullated bed reaction zone further includes aplenum chamber below the expanded catalyst zone and bounded by adistributor grid plate and the bottom of the reactor vessel, and adisengagement zone above the expanded catalyst zone. Both the plenumchamber and the disengagement zone contain hydrocarbonaceous liquid inthe absence of particulate catalyst.

The ebullated bed heavy oil processing system further includes a port atthe top of the reactor for introducing particulate catalyst and a portat the bottom of the reactor for removing particulate catalyst; a portat the bottom of the reactor for introducing heavy oil feedstock andhydrogen gas under pressure and at elevated temperature into thereactor, and a port near the top of the reactor through which upgradedheavy oil, unreacted hydrogen and gaseous products are removed. Heavyoil feed entering the reaction zone passes in turn through a plenumchamber below the expanded catalyst zone, through the distributor gridplate supporting the expanded catalyst zone, and upward through theexpanded catalyst zone. A recirculation conduit and a recirculationreceiver are included in the ebullated bed reaction zone to facilitatecirculation of the hydrocarbonaceous liquid via a circulation pumpthrough the reaction zone. The circulation pump can be locatedexternally as in H-Oil or H-Coal ebullating bed reactor systems, orinternally, e.g., LC-Fining ebullating reactor system.

Heavy Oil Feedstock The heavy oil feedstock may comprise any fossil fuelfeedstock and/or fraction thereof including, but not limited to, one ormore of heavy crude oil, a reduced crude oil, petroleum residuum,atmospheric tower bottoms, vacuum tower bottoms, tar sands bitumen,shale oil, liquefied coal, coal tar, reclaimed oil, heavy residual oilsgenerated by solvent deasphalting of petroleum residua including the DAOand pitch fractions from the deasphalting process, and other residuumfractions. In one embodiment, the heavy oil feedstock includes asignificant fraction of high boiling point hydrocarbons, with boilingpoints at or above 343° C. (650° F.). In one embodiment, the heavy oilfeedstock has a boiling range at or above 524° C. (975° F.). Heavy oilfeedstocks which can be treated in the present process containasphaltenes. Asphaltenes are complex hydrocarbon molecules that includea relatively low ratio of hydrogen to carbon that is the result of asubstantial number of condensed aromatic and naphthenic rings withparaffinic side chains. The asphaltene fraction also contains a highercontent of sulfur and nitrogen than does crude oil or the rest of thevacuum residuum, and it also contains higher concentrations ofcarbon-forming compounds.

Particulate Catalyst: In the process, the heavy oil is converted in ahydroconversion reaction zone, which contains an expanded catalyst zonecomprising a particulate catalyst. The particulate catalyst generallyincludes one or more metals known to have hydrogenation activity affixedonto a porous refractory base (“a carrier”) comprising one or more ofalumina, iron oxide, silica, magnesia, titania, zeolite,silica-aluminate, phosphorous or various combinations of these. Thealumina in the base can be in several forms including amorphous, alpha,gamma, theta, boehmite, pseudo-boehmite, gibbsite, diaspore, bayerite,nordstrandite and corundum. In one embodiment, the alumina is boehmiteor pseudo-boehmite. In one embodiment, carbon may be used as a support.In one embodiment, the base may be an ore or mineral or waste product ora manufactured form of alumina. The metals that are used in theparticulate catalyst include base metals or compounds thereof, selectedfrom Group VIB metals or Group VIII metals of the Periodic Table, orcombinations thereof. Representative metals that are used include one ormore of the Group VIB metals, such as chromium, molybdenum and tungsten,and one or more of the Group VIII metals, such as iron, cobalt andnickel. In one embodiment, the particulate catalyst is a composite of aGroup VI metal or compound thereof and a Group VIII metal or compoundthereof.

In one embodiment, the metals or metal compounds, e.g., metal oxide,metal hydroxide, metal sulfide and combinations thereof, are supportedon the porous refractory base such as alumina. Exemplary particulatecatalysts include but are not limited to molybdenum, cobalt molybdenum,nickel sulfide, nickel tungsten, cobalt tungsten and nickel molybdenumon an alumina support. The particulate catalyst comprises 1 wt. % to 20wt. % molybdenum in one embodiment; and from 3 wt. % to 15 wt. %molybdenum in a second embodiment.

In one embodiment, the particulate catalyst has a nominal particle sizeof at least 0.65 mm ( 1/40″). In some embodiments, the particulatecatalyst has a spherical shape having a particle diameter of at least0.65 mm. In another embodiment, the particulate catalyst comprisespellets or grains that are 1 to 1.5 mm in size to facilitate suspensionby the liquid phase in the reactor. In one embodiment, the particulatecatalyst has a cylindrical shape having a cross sectional diameter inthe range from 1.0 mm (0.04 inch) mm to 10 mm (0.4 inch), and a lengthnormal to the cross sectional diameter such that the length to diameterratio is in the range from 2 to 8. In one embodiment, the particulatecatalyst has an irregular shape. While it is desirable to employparticulate catalysts with uniform dimensions, a small fraction ofparticulate catalyst may have dimensions that fall outside of theseranges.

The particulate catalyst has a high surface area and a high pore volume(as measured by nitrogen adsorption method). In general, the surfacearea of the particulate catalyst is greater than 100 m²/g. In oneembodiment, the surface area of the particulate catalyst is in the rangefrom 100 to 350 m²/g, or in the range from 150 to 350 m²/g in a secondembodiment. In general, the pore volume of the particulate catalyst isgreater than 0.4 cm³/g. In one embodiment, the pore volume of theparticulate catalyst is in the range from 0.4 cm³/g to 1.2 cm³/g. In oneembodiment, the pore volume of the particulate catalyst is in the rangefrom 0.4 cm³/g to 1.0 cm³/g.

Details regarding particulate catalysts and methods for making thereofcan be found in U.S. Pat. Nos. 7,803,266; 7,185,870; 7,449,103;8,024,232; 7,618,530; 6,589,908; 6,667,271; 7,642,212; 7,560,407,6,030,915, U.S. Pat. No. 5,980,730, U.S. Pat. No. 5,968,348, U.S. Pat.No. 5,498,586, and US Patent Publication Nos. 2011/0226667,2009/0310435, 2011/0306490, the relevant disclosures are included hereinby reference.

Slurry Catalyst In one embodiment, the slurry catalyst is prepared fromat least one Primary metal precursor (e.g., a Group VIB metal precursor)and at least one Promoter metal precursor (e.g., a Group VIB metalprecursor different from the Primary metal precursor, or a Group IIBmetal precursor, or a Group VIII metal precursor such as Ni, or a GroupIVA metal precursor such as Ti). In another embodiment, the catalyst isprepared from at least a Primary metal precursor with no Promoter metaladded. In yet another embodiment, the catalyst is prepared from at leasta Group VIII metal such as a nickel compound as the Primary metalcomponent, with or without the subsequent addition of other metals asPromoter metals. In yet another embodiment, the catalyst is preparedfrom a double salt precursor in solution. The double salt precursorcontains at least two different metal cations, e.g., prepared from atleast two different metal precursor feeds. Multiple Promoter metalprecursors can be used as the feedstock, e.g., different Group VIIImetal precursors are used such as Ni and Co, metal precursors comprisingdifferent “d” elements such as Fe and Zn, or Cu and Fe. Multiple Primarymetal precursors can be used as co-catalyst, e.g., Mo and W.

In one embodiment, at least one of the metal precursors may be oilsoluble, oil dispersible, water soluble and/or water dispersible in thepreparation of the slurry catalyst. The metal precursors can be providedas an elemental metal or as a metal compound. The metal precursors canbe added in the solid state. In one embodiment, one of the metalprecursors can be added in the solid state, while the second metalprecursor can be added in the solute state. The metal precursors can bethe same or different, e.g., all organic compounds, all inorganiccompounds, or one organic and one inorganic. The metal precursors in oneembodiment can be catalytically active, e.g., a reagent grade metalsulfide or a beneficiated ore.

In one embodiment, at least one of the metal precursors is an organiccompound selected from metal salts of organic acids, such as acyclic andalicyclic aliphatic, carboxylic acids containing two or more carbonatoms. Non-limiting examples include acetates, oxalates, citrates,naphthenate and octoates. In another embodiment, the metal precursorsare selected from salts of organic amines. In yet another embodiment,the metal precursors are selected from organometallic compounds, e.g.,chelates such as 1,3-diketones, ethylene diamine, ethylene diaminetetraacetic acid, phthalocyanines and mixtures thereof. In anotherembodiment, the organic metal precursors are selected from salts ofdithiolate, dithiocarbamate, and mixtures thereof. An example is a GroupVIII dithiocarbamate complex, or a soluble molybdenum-containingorganophosphorodithioate such as molybdenum dialkyl dithiophosphate forthe Group VIB metal precursor. The metal precursors can also besulfur-containing organic compounds, e.g., a chelate compound withsulfur as a coordinating atom such as sulfhydryl S—H, or a molybdenumoxysulfide dithiocarbamate complex (Molyvan A).

In one embodiment, the Group VIB metal precursor (as a Primary metal ora Promoter metal) is selected from the group of alkali metal or ammoniummetallates of molybdenum in organic solvents such as a normal alkane,hydrocarbons, or petroleum products such as distillate fractions whereinthe molybdenum compound is allowed to subsequently decompose underpressure and temperature, prior to or concurrent with the addition ofthe Promoter metal precursor. In another embodiment, the Group VIB metalprecursor feed is a water-soluble salt, e.g., oxides and polyanions suchas molybdates, tungstates, chromates, dichromates, etc. In oneembodiment, the Group VIB metal precursor is selected from the group ofalkali metal heptamolybdates, alkali metal orthomolybdates, alkali metalisomolybdates, phosphomolybdic acid, and mixtures thereof. In anotherembodiment, it is selected from the group of molybdenum (di- and tri)oxide, molybdenum carbide, molybdenum nitride, aluminum molybdate,molybdic acid (e.g. H₂MoO₄), or mixtures thereof. In yet anotherembodiment, the Group VIB metal compound is an organometallic complex,e.g., oil soluble compound or complex of transition metal and organicacid, selected from naphthenates, pentanedionates, octoates, acetates,and the like. Examples include molybdenum naphthanate and molybdenumhexacarbonyl.

In one embodiment, the Promoter metal precursor is a Group VIII metalcompound selected from the group of sulfates, nitrates, carbonates,sulfides, oxysulfides, oxides and hydrated oxides, ammonium salts andheteropoly acids thereof. In one embodiment, the Group VIII metalprecursor is a water-soluble compound such as acetate, carbonate,chloride, sulfate, nitrate, acetylacetone, citrate, and oxalate, e.g.,nickel nitrate, nickel sulfate, nickel acetate, nickel chloride, etc.,and mixtures thereof. In another embodiment, the metal precursor is acompound which is at least partly in the solid state, e.g., awater-insoluble nickel compound such as nickel carbonate, nickelhydroxide, nickel phosphate, nickel phosphite, nickel formate, nickelsulfide, nickel molybdate, nickel tungstate, nickel oxide, nickel alloyssuch as nickel-molybdenum alloys, Raney nickel, or mixtures thereof.

In one embodiment, polar aprotic solvents are used in conjunction withinorganic metal precursors for the preparation of the precursor feed.The organic solvent, e.g., an organosulfur compound which is compatiblewith both the inorganic metal precursor and the oil feedstock, acts as asolvent to dissolve the inorganic metal precursor. With the use of theorganic solvent, the inorganic metal precursor becomesmiscible/dispersible in a hydrocarbon diluent or heavy oil feedstock,thus alleviating the need for a transforming step. Examples of organicsolvents include but are not limited to polar aprotic solvents such asN-Methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide(DMAC), hexamethylphosphortriamide (HMPA), dimethyl sulfoxide (DMSO),tetrahydrofuran, propylene carbonate, dimethyl sulfite,N-nitrosodimethylamine, γ-butyrolactone, N:N dimethyl formamide,dimethyl carbonate, methyl formate, butyl formate and mixtures thereof.The organic solvent can be used as neat liquids, or in combination withother inexpensive solvents such as water or methanol. Examples ofinorganic metal precursors for use with the organic solvent include butare not limited to molybdenum oxide, sulfide, or oxysulfide of thegeneral formula Moo_(x)S_(y) wherein x≧0, y≧0.

In one embodiment, the Promoter metal precursor is a Group IIB metalprecursor such as zinc. Zinc is a less expensive material and moreenvironmentally friendly than other metal precursors such as nickel.Examples include but are not limited to Group JIB inorganic compoundssuch as zinc sulfate, zinc nitrate, zinc carbonate, zinc sulfide, zincoxysulfide, zinc oxide and zinc hydrated oxide, zinc ammonium salts andheteropoly acids thereof. In one embodiment, the Group VIII or Group IIBmetal precursor is a compound which is at least partly in the solidstate, e.g., a water-insoluble nickel compound such as nickel carbonate,nickel hydroxide, nickel phosphate, nickel phosphite, nickel formate,nickel sulfide, nickel molybdate, nickel tungstate, nickel oxide, nickelalloys such as nickel-molybdenum alloys, Raney nickel, or mixturesthereof.

In one embodiment with the addition of at least a Promoter metal, theweight ratio of the Promoter metal component (each individual Promotermetal component) to the Primary metal component is in any of the ranges:from 1 wt. % to 90 wt. %; from 2 wt. % to 50 wt. %; from 5 wt. % to 30%;and from 10 wt. % to 20 wt. %.

The slurry catalyst can also be prepared from a powder as metalprecursor feedstock, e.g., rework material. In one embodiment, reworkmaterials include catalyst fines generated in the making of (unsulfided)supported catalyst and/or unsupported (mixed Group VIII and Group VIBmetal) catalyst precursors used for hydroconversion processes known inthe art. In one embodiment, the rework material is generated from asupported catalyst precursor, e.g., pellets or extrudates with a porousrefractory base such as alumina. In another embodiment, the reworkmaterial is from a re-generated or recycled particulate catalyst.

In one embodiment, rework materials for use as metal precursor feedcomprise scrap/discarded/unused materials generated in any step of thepreparation of (unsulfided) supported catalyst or bulk catalystprecursors. Rework can be generated from any of the forming, drying, orshaping of the catalyst precursors, or formed upon the breakage orhandling of the catalyst precursor in the form of pieces or particles,e.g., fines, powder, and the like. In the process of making catalystprecursors, e.g., by spray drying, pelleting, pilling, granulating,beading, tablet pressing, bricketting, using compression method viaextrusion or other means known in the art or by the agglomeration of wetmixtures, forming shaped catalyst precursors, rework material isgenerated.

Rework materials can also be generated from commercially availablecatalyst products, including but not limited to supported andself-supported catalyst such as ICR™ supported catalyst from AdvancedRefining Technologies LLC, Nebula™ bulk catalyst from Albermale, or CRI™NiMo alumina supported catalyst from Criterion Catalyst & Technologies,reduced to a size of less than 300 μm. In one embodiment, reworkmaterial consists essentially of unsulfided catalyst precursors, madewith or without the use of diluents or binders such as alumina, silicaalumina, cellulose and the like. In another embodiment, the reworkmaterial comprises the same material as used in the particulatecatalyst, ground to a size of less than 300 μm.

In one embodiment, the rework material is prepared in a method asdescribed in US Patent Application No. 20110306490, incorporated hereinby reference in its entirety. The support material, e.g., alumina, ironoxide, silica, magnesia, titania, zeolite, etc., is first ground toparticles of less than 300 μm. Catalytic materials, e.g., double metalprecursors or single metal precursors such as ammonium heptamolybdate,or any soluble form of molybdenum, etc. are then deposited (impregnated)onto the ground base. The impregnated base is dried, then ground to aparticle size of 1 to 300 μm. In one embodiment, the deposition ofcatalytic materials is followed by calcination so the catalyticmaterials sinter with the metal in the support to effect loading. Thedeposition of catalytic materials can be carried out more than once tomaximize the catalyst loading, or different metal precursors can bedeposited onto the ground support base at the same time or as differentlayers for multi-metallic catalyst fines.

In one embodiment, the rework material for use as metal precursor feedhas an average particle size of less than 300 μm and greater than 1 μm.In a second embodiment, the average particle size is between 2-100 μm.In a third embodiment, in the range from 2 to 50 μm. The rework materialcan be ground, pulverized, or crushed to the desired particle size usingtechniques known in the art, e.g., via wet grinding or dry grinding, andusing equipment known in the art including but not limited to hammermill, roller mill, ball mill, jet mill, attrition mill, grinding mill,media agitation mill, etc.

Examples of supported and unsupported catalyst precursors and processfor making thereof, for the subsequent generation of rework materials,are as disclosed in U.S. Pat. Nos. 2,238,851; 4,066,574; 4,341,625;4,113,661; 5,841,013; 6,156,695; 6,566,296; 6,860,987; 7,544,285;7,615,196; 6,635,599; 6,635,599; 6,652,738; 7,229,548; 7,288,182;6,162,350; 6,299,760; 6,620,313; 6,758,963; 6,783,663; 7,232,515;7,179,366; 6,274,530; US Patent Publication Nos. US20090112011A1,US20090112010A1, US20090111686A1, US20090111685A1, US20090111683A1,US20090111682A1, US20090107889A1, US20090107886A1, US20090107883A1, andUS2007090024, the relevant disclosures with respect to the catalystprecursor and catalyst composition are included herein by reference.

Method for Making the Slurry Catalyst: In one embodiment with the use ofinorganic metal precursors as feedstock, a catalyst precursor is formedfrom the reaction of the inorganic metal precursors, followed bysulfiding with the addition of at least a sulfiding agent at a molarratio of sulfur to metal ratio of at least 1.5:1 in one embodiment, atleast 2:1 in a second embodiment, and at least 3:1 in a thirdembodiment. In yet another embodiment, the Primary metal precursor isfirst sulfided prior to the addition of the Promoter metal precursor(unsulfided), generating a promoted sulfided catalyst precursor. Inanother embodiment, a Primary metal precursor (unsulfided) is broughtinto contact with a sulfided Promoter metal precursor and the mixturemay or may not be sulfided again to form a sulfided catalyst precursor.In yet another embodiment, the Primary metal precursor and the Promotermetal precursor(s) are separately sulfided and combined. In anotherembodiment without any Promoter metals, the Primary metal precursor feedis sulfided before transformation with a hydrocarbon diluent. Thesulfiding step in one embodiment is carried out at a temperature fromambient to 300° F. for a period of up to 24 hours, and at a pressurefrom 0 to 3000 psig. The sulfiding agent can be any of hydrogen sulfide,ammonium sulfide solution, elemental sulfur, and in one embodiment, sourwater before or after treatment.

In one embodiment, the water-based (sulfided or unsulfided) catalystprecursor is subject to a reduction step at temperatures above ambientwith the introduction of at least a reducing agent, e.g., hydrogen, ahydrocarbon, etc. In another embodiment, the water based catalystprecursor after sulfiding is brought in contact with a hydrocarbontransforming agent (“diluent”) and transformed from a water-basedcatalyst (hydrophilic) to an oil-based active catalyst (hydrophobic). Inone embodiment, the weight ratio of the water-based catalyst to thehydrocarbon diluent ranges from 1:10 to 10:1. In a second embodiment,the weight ratio of the water-based catalyst to the hydrocarbon diluentranges from 1:5 to 5:1. In a third embodiment, from 1:5 to 1:1. In yetanother one embodiment, the ratio of water-based catalyst to hydrocarbondiluent ranges from 2:1 to 5:1. In another embodiment, the ratio rangesfrom 1:1 to 2:1. The nature of the hydrocarbon is not critical, and cangenerally include any hydrocarbon compound, acyclic or cyclic, saturatedor unsaturated, un-substituted or inertly substituted, and mixturesthereof, which is liquid or solid at ambient temperatures. In oneexample, the hydrocarbon compound is derived from petroleum, includingmixtures of petroleum hydrocarbons characterized as virgin naphthas,cracked naphthas, Fischer-Tropsch naphtha, light cat cycle oil, heavycat cycle oil, and the like, typically those containing from about 5 toabout 30 carbon atoms. In one embodiment, the hydrocarbon compound is avacuum gas oil (VGO). In yet another embodiment, the diluent is amixture of heavy oil and VGO.

In one embodiment, the sulfiding and/or the transformation step(s) canbe eliminated by mixing a solution containing the metal precursor(s)directly with the heavy oil feed stock or a feedstock mixture (with ahydrocarbon diluent). The mixing can be at a high shear rate, for adispersion of metal precursors in the heavy oil feed as an emulsion withdroplets in sizes ranging from 0.1 to 300 μm. As heavy oil feedstock hasavailable sulfur source for sulfidation and under sufficient conditionsfor the release of the sulfur source (e.g., H₂S), an emulsion of slurrycatalyst can be formed when the metal precursor(s) are mixed directlywith the heavy oil feedstock and become sulfided under appropriateconditions. In one embodiment, the in-situ sulfidation occurs underhydrotreating conditions, e.g., at a temperature ranging from 400° C.(752° F.) to 600° C. (1112° F.), and a pressure ranging from 10 MPa(1450 psi) to 25 MPa (3625 psi). In one embodiment, additional sulfidingagents can be added at the beginning of the process to get the in-situsulfidation started. In another embodiment, additional sulfiding agentscan be continuously or intermittently added to the in-situ sulfidingprocess with a heavy oil feedstock.

In one embodiment wherein a sulfur-containing organic solvent, e.g.,DMSO, is employed in conjunction with the metal precursor feedstock, thesulfiding step can be omitted. The metal precursor/solvent mixture canbe brought into contact directly with a hydrocarbon diluent or a heavyoil feed stock, and optionally a sulfiding agent, wherein a sulfidedactive slurry catalyst is generated.

In one embodiment with the use of rework materials for making the slurrycatalyst, the rework material is combined with a diluent (carrier) andoptionally, a sulfiding agent, e.g., H₂S, elemental sulfur, or ammoniumsulfide, forming an unsulfided slurry catalyst (if no sulfiding agentadded) or a sulfided slurry catalyst (if sulfiding took place) to beinjected into the ebullated bed reactor. The diluent for use with therework materials in one embodiment is a hydrocarbon diluent (as used asa transforming agent with the water-based slurry catalyst made frommetal precursor feed) e.g., VGO, cycle oil, gasoline, distillate,naphtha, light cycle oil, benzene, toluene, xylene, diesel oil, heptane,etc. In another embodiment, water itself can be used as the carrier. Inanother embodiment, the rework materials can be slurried directly in aheavy oil feedstock, or a mixture of a heavy oil feedstock andhydrocarbon diluent, forming a sulfided slurry catalyst ex-situ prior tofeeding to the ebullated bed reactor. In yet another embodiment, therework materials are slurried directly in the heavy oil feedstock undersufficient sulfiding conditions for in-situ sulfiding to take place,generating a sulfided slurry catalyst in the ebullating bed reactor.

In one embodiment, a sufficient amount of rework material is employed asa powder in an amount sufficient for the formation of the slurrycatalyst, and to provide a slurry catalyst dosage of 5 to 5000 ppmPrimary metal (e.g., Mo) to total heavy oil feedstock. The amount ofpowder (rework materials) ranges from 2 to 60 wt. % of total weight ofthe hydrocarbon diluent and/or heavy oil feedstock in one embodiment; 5to 40 wt. % in a second embodiment; less than 1 wt. % in a thirdembodiment for a low Primary metal dosage; and a sufficient amount ofrework material is used for a dosage ranging from 20 to 1000 ppm ofPrimary metal to heavy oil feedstock to the ebullating bed system in afourth embodiment. In another embodiment, a sufficient amount of reworkmaterial is used for a dosage of 5 to 100 ppm Primary metal to heavy oilfeedstock.

The slurry catalyst in one embodiment may optionally comprise othercomponents including but not limited to pore forming agents, emulsifieragents, surfactants, sulfur additives, sulfiding agents, stabilizers,binder materials, phosphorus compounds, boron compounds, additionaltransition metals, rare earth metals or mixtures thereof, depending onthe envisaged catalytic application. The optional components may beadded to the slurry catalyst directly, or added to the diluent/carrierfor subsequent mixing with the rework material/catalyst precursor.

In one embodiment, the slurry catalyst to the dual catalyst systemcomprises solely of a slurry catalyst made from metal precursor reagentsas feedstock and pre-sulfided. In another embodiment, the slurrycatalyst comprises solely of a catalyst made from rework materials,provided to the system as a ground catalyst. In another embodiment, therework materials are dispersed in a hydrocarbon diluent or othersuitable liquid carrier and introduced to the system as an unsulfidedslurry catalyst, subsequently sulfided in-situ upon contact with theheavy oil feedstock under sulfiding conditions. The rework materials canalso be introduced to the ebullating bed system in a pre-sulfided formas a slurry catalyst.

In one embodiment, the slurry catalyst comprises slurry catalyst madefrom rework materials as well as metal precursor reagents, at a weightratio ranging from 5:95 to 95:5, with the weight ratio of slurrycatalyst from rework materials to slurry catalyst from metal precursorreagents varying depending on various factors, including the type ofheavy oil feedstock to be processed, operating conditions of the system,availability of supplies, etc.

Properties of the Slurry Catalyst. The slurry catalyst is generallysized to remain entrained in at least a portion of the fluid that isupflowing through the ebullated bed reaction zone, with a sufficientsize range to facilitate removing the catalyst from a product liquidusing filtering. The slurry catalyst has an average particle size ofgreater than 1 μm and less than 500 μm in one embodiment; in a rangefrom 1 to 300 μm in a second embodiment; at least 5 μm in a thirdembodiment; in a range from 5 to 70 μm in a fourth embodiment; in arange from 5 to 50 μm in a fifth embodiment; and in a range from 2 to 30μm in a sixth embodiment.

The slurry catalyst is characterized as having an internal pore volumethat significantly increases the effectiveness of the dual catalystsystem in the heavy oil upgrade process. The slurry catalyst has a porevolume of greater than 0.4 cm³ per gram (cm³/g) of catalyst in a solidform in one embodiment; greater than 0.6 cm³/g in a second embodiment;greater than 0.8 cm³/g in a third embodiment; greater than 1.2 cm³/g ina fourth embodiment; in the range from 0.4 cm³/g to 1.8 cm³/g in a fifthembodiment; and in the range from 0.6 cm³/g to 1.5 cm³/g in a sixthembodiment.

In one embodiment, the slurry catalyst is characterized as having apolymodal pore distribution with at least a first mode having at leastabout 80% pore sizes in the range from 5 to 2,000 Angstroms in diameter,a second mode having at least about 70% of pore sizes in the range from5 to 1,000 Angstroms in diameter, and a third mode having at least 20%of pore sizes of at least 100 Angstroms in diameter. As used herein,polymodal includes bimodal and higher modal. In one embodiment, at least30% of pore sizes are >100 Angstroms in diameter. In another embodiment,at least 40%. In yet another embodiment, at least 50% are in the rangefrom 50 to 5000 Angstroms in diameter. In one embodiment, the slurrycatalyst (made from metal precursor feed) is characterized as having atleast 65% of the pore volume ranging from 100 to 1000 Angstroms.

In one embodiment, the slurry catalyst is characterized as having arelatively high total surface area, as determined by the nitrogen BETmethod, of at least 100 m²/g (of catalyst). In one embodiment, thesurface area is at least 200 m²/g. In another embodiment, the surfacearea is from 200 to 900 m²/g. In a fourth embodiment, it is from 50 to800 m²/g. In a fifth embodiment, from 100 to 400 m²/g. In a sixthembodiment, from 300 to 800 m²/g. In a seventh embodiment, the slurrycatalyst has a surface area of at least 300 m²/g.

The slurry catalyst comprises 0.5 wt. % to 50 wt. % of at least aPrimary metal, such as molybdenum (based on solid weight) in oneembodiment; from 1 wt. % to 45 wt. % molybdenum in a second embodiment;or from 3 wt. % to 40 wt. % molybdenum in a third embodiment.

In one embodiment of a slurry catalyst prepared from metal precursorfeedstock, the slurry catalyst (as a multi-metallic or single metalcatalyst) is of the formula(M^(t))_(a)(L^(u))_(b)(S^(v))_(d)(C^(w))_(e)(H^(x))_(f)(O^(y))_(g)(N^(z))_(h),wherein M is a Primary metal selected from Group VIB metals, non-nobleGroup VIII metals, Group IIB metals; L is optional as a Promoter metaland L is a metal that is different from M, L is at least one of a GroupVIII metal, Group VIB metal, Group IVB metal, and Group IIB metal; b>=0;0=<b/a=<5; 0.5(a+b)<=d<=5(a+b); 0<=e<=11(a+b); 0<=f<=18(a+b);0<=g<=5(a+b); 0<=h<=3(a+b); t, u, v, w, x, y, z, each representing totalcharge for each of: M, L, S, C, H, O and N, respectively; andta+ub+vd+we+xf+yg+zh=0. In one embodiment of a multi-metallic slurrycatalyst, the Primary metal M is molybdenum and the Promoter metals arenickel and titanium. In another embodiment, the slurry catalyst issingle metallic with nickel as the Primary metal M. In yet anotherembodiment, the Primary metal M of the single metallic slurry catalystis molybdenum.

Slurry Catalyst Addition: In the dual catalyst system, the slurrycatalyst is provided as a single addition of slurry catalyst to thereaction zone in one embodiment, or as an intermittent addition to thereaction zone in a second embodiment, or as a continuous addition to thereaction zone over an extended time period in a third embodiment.Intermittent addition may be done periodically, or on an as neededbasis. In one embodiment, intermittent addition includes dosing thereaction zone with high levels of the slurry catalyst, and thenoperating the reaction zone without added slurry catalyst until theamount of slurry catalyst in the recirculating liquid reaches aspecified minimum amount within the reaction zone before repeating theaddition of slurry catalyst. The slurry catalyst can be provided at aconstant addition rate or at a varying addition rate depending on theoperating conditions, e.g., the properties of the heavy oil feedstock,run time, etc., amongst other factors.

The slurry catalyst is added to the ebullated bed system as a liquidphase slurry. The liquid phases includes a carrier fluid, such as anaqueous phase, the heavy oil feedstock, or a hydrocarbon diluent, e.g.,hydrocarbons boiling in the heavy diesel range or the LVGO range,including a boiling range from 400° to 700° F., or a full VGO rangeboiling from 650-950° F. In one embodiment, the slurry catalyst isprepared by combining rework material with the carrier fluid. In anotherembodiment, the slurry catalyst is prepared in a liquid phase fromcatalyst precursor materials.

In one embodiment, the slurry catalyst is supplied to the reaction zone,where it is combined with the heavy oil feedstock in the reaction zone,at a temperature range from ambient temperature to the reactiontemperature within the reaction zone. In one embodiment, the suppliedslurry catalyst is supplied to the reaction zone at a temperature in therange from 50° F. to 850° F. Slurry catalyst supplied at an elevatedtemperature may be preheated prior to introduction to the reaction zone.In one embodiment, at least a portion of the slurry catalyst passesthrough a preheat furnace prior to introduction to the reaction zone. Inone embodiment, at least a portion of the slurry catalyst is preheatedby addition of a hot media, such as heated hydrogen, heated carrierfluid or heated heavy oil feedstock, prior to introduction to thereaction zone.

In one embodiment, at least a portion of the slurry catalyst is suppliedto at least a portion of the heavy feedstock prior to introduction tothe reaction zone. In general, the heavy oil feedstock is preheatedprior to introduction to the reaction zone, and is introduced to thereaction zone at a temperature up to and including the reactiontemperature in the reaction zone. In one embodiment, the heavy oilfeedstock is introduced at a temperature that is somewhat lower than thereaction zone temperature, in order to absorb exothermic heat that isgenerated from the exothermic reactions occurring in the reaction zone.In one embodiment, the slurry catalyst is added to the heavy oilfeedstock prior to preheating the heavy oil feedstock; the slurrycatalyst/heavy oil feedstock mixture is thus preheated together to adesired elevated temperature. In one embodiment, the slurry catalyst isprovided to the preheated heavy oil feedstock, and the mixture isintroduced to the reaction zone.

In one embodiment, the slurry catalyst is presulfided, such thatadditional sulfur addition to the catalyst is not required for thecatalyst to possess sufficient catalytic activity for the desiredreactions in the reaction zone. In embodiments, the slurry catalystcomprises molybdenum and sulfur in the atomic ratio Mo/S within therange from 1/1 to 1/3 prior to introduction to the reaction zone. In oneembodiment, the slurry catalyst is provided to the reaction zone in asulfur containing fluid, such that the slurry catalyst is sulfided priorto or during introduction to the reaction zone.

A sufficient amount of slurry catalyst is introduced into the dualcatalyst system for a total solid concentration in heavy oil feedstockranging from 5 to 1000 ppm in one embodiment; from 5 to 700 ppm in asecond embodiment; and from 10 to 500 ppm in a third embodiment. In oneembodiment wherein rework is employed, the total solid concentrationranges from 50-500 ppm. In another embodiment, the total solidconcentration ranges from 10 to 300 ppm.

In terms of catalytically active materials (e.g., Primary metalprecursor such as Mo), a sufficient amount of slurry catalyst issupplied for a Primary metal concentration ranging from 5 to 1000 ppm ofPrimary metal in heavy oil feedstock in one embodiment; from 10 to 750ppm in a second embodiment; from 25 to 500 in a third embodiment; and 50to 250 ppm in a fourth embodiment. In one embodiment wherein rework isemployed, the Primary metal concentration ranges from 5 to 500 ppm.

Hydroprocessing Operation with Dual Catalyst System: Much of thebeneficial upgrading reactions occur within the expanded catalyst zone,where the heavy oil feedstock containing the slurry catalyst contactsthe particulate catalyst in the presence of hydrogen, at suitablereaction temperatures. In one embodiment, upgrading reaction conditionswithin the expanded catalyst zone include a temperature in the rangefrom 204° to 482° C. (400° to 900° F.) and a pressure within a rangefrom 500 to 5000 psig (pounds per square inch gauge) (3.5-34.6 MPa). Inone embodiment, the upgrading reaction temperature is in the range from315° to 480° C. (600° to 900° F.), or in the range from 370° to 480° C.(700° to 900° F.) or in the range from 390° to 450° C. (740° to 840°F.). In one embodiment, upgrading reaction conditions within theexpanded catalyst zone include a pressure from 1000 psig to 3500 psig(7.0-24.4 MPa). In carrying out the upgrading process, hydrogen isusually provided to the expanded catalyst zone within the range from2000 to 10,000 standard cubic feet (scf) per barrel of feedstock, theoverall hydrogen consumption being in the range from 300 to 2000 scf perbarrel of liquid hydrocarbon feed (53.4-356 m³ H₂/m³ feed).

The ebullated bed heavy oil system with the dual catalyst feed type isparticularly suitable for upgrading certain types of heavy oil underconditions, wherein the catalysts deactivate rapidly due, for example,to coke and metals deposition on the catalyst. Such a system is alsoparticularly effective for higher temperature and higher conversionoperations. During operation of the ebullated bed heavy oil processingsystem for upgrading heavy oil, the heavy oil is heated to a temperatureat which the heavy oil molecules within the feedstock tend to undergothermal cracking to form free radicals of reduced chain length. Thesefree radicals have the potential of reacting with other free radicals toproduce coke precursors and sediment within the reactor. It is onefunction of catalysts within the system to react with the free radicals,forming stable molecules of reduced molecular weight and boiling point.

In conventional ebullated bed heavy oil processing systems, there areseveral zones in which the heated heavy oil is not in contact with acatalyst. For example, the heavy oil is heated to reaction temperaturein a heating zone external to the reaction zone. It then passes from theheating zone through a feed port into the reactor, through the plenumchamber below the expanded catalyst zone, through the distributor platesupporting the expanded catalyst zone, and upward through the expandedcatalyst zone. Within the plenum chamber and within the disengagementzone, at least, the heavy oil is at a high temperature but without thebenefit of a porous supported catalyst, such as the particulatecatalyst. Even the expanded catalyst zone has regions of higher catalystdensity, and regions of lower catalyst density. In these lower densityregions, the heavy oil has an increased tendency to form free radicalswhich tend to react with other free radicals to form sediment beforethese free radicals contact with a catalyst particle and getdeactivated. Upgraded heavy oil then passes from the expanded catalystzone to the disengagement zone at temperatures which are sufficientlyhigh to cause the heavy oil to form additional free radicals. In theabsence of catalyst, these additional free radicals tend to react withother free radicals, to form additional sediment or coke precursors.

With the use of the dual catalyst system, and particularly with theslurry catalyst having a high pore volume, a high surface area and anaverage particle size of at least 1 μm, the use of the slurry catalystallows an increase in the conversion of the heavy oil while reducing theformation of coke precursors and sediment in high temperature regionswithin the reaction zone. The slurry catalyst is sized to be carriedwith the flowing heavy oil in the ebullated bed heavy oil processingsystem, and thus to distribute in the hydrocarbonaceous liquid throughthe ebullated bed reaction zone, including the feed inlet port, thelower region, the expanded catalyst zone and the upper region. In atleast the feed inlet, the plenum chamber, and the disengagement zone,the slurry catalyst is the sole catalyst for suppressing sedimentformation. In the expanded catalyst zone, the slurry catalyst maintainscatalytic activity in regions of lower particulate catalyst density, andprovides additional reactivity to control sediment formation.

The slurry catalyst provides additional catalytic hydrogenationactivity, both within the expanded catalyst zone, the recirculationconduit and the upper and plenum chambers. The effect of the slurrycatalyst capping free radicals outside of the particulate catalystminimizes formation of sediment and coke precursors, which are oftenresponsible for deactivating the particulate catalyst. This has theeffect of reducing the amount of particulate catalyst that wouldotherwise be required to carry out a desired hydroprocessing reaction.It also reduces the rate at which the particulate catalyst must bewithdrawn and replenished. The use of the slurry catalyst reduces theformation of sediment and coke precursors at least 10% over anebullating bed system without the slurry catalyst in one embodiment; atleast 20% in a second embodiment, and at least 25% in a thirdembodiment.

Addition of the slurry catalyst to the ebullated bed reaction zonesignificantly increases the operational flexibility when operating theupgrading process within the reaction zone. In one aspect, the additionrate of the slurry catalyst can vary over a wide range, depending onrequirements of the specific use of the process, without affecting theoverall operability of the process. In another aspect, even a relativelylow addition rate of the slurry catalyst has a significant effect on theproduct quality of the upgraded heavy oil that is recovered from theprocess. In terms of the hydrogenation component distribution betweenthe particulate catalyst and the slurry catalyst in the ebullated bedreaction zone, less than 50% by weight of the hydrogenation component(e.g. molybdenum) in the reaction zone is associated with the slurrycatalyst. In one embodiment, 1 wt. % to 50 wt. % of the hydrogenationcomponent in the ebullated bed reaction zone is associated with theactivity of the slurry catalyst.

One benefit realized from controlling or reducing sediment in theupgraded heavy oil is to avoid fouling in downstream equipment,including separation vessels, distillation columns, heat exchangers, andthe like, in addition to meeting upgraded heavy oil productspecifications. In one embodiment, use of the slurry catalyst canprovide added operational flexibility. In some conventional ebullatedbed processes without the use of slurry catalyst, operating conditionsare controlled to at least some extent by the capabilities of downstreamprocessing equipment for handling sediment and coke precursors in theupgraded heavy oil from the ebullated bed process. Use of the slurrycatalyst as described herein suppresses the formation of sediment andcoke precursors. In turn, this will also improve some of the otherproduct qualities depending on the conditions.

One suitable response to the decreased sediment formation is to increasethe reaction temperature in the ebullated bed reaction zone to increaseconversion of the heavy oil to produce a lighter, more valuable productmix of an upgraded product. Increased conversion will also improve otherproduct qualities, depending on the features of a specific embodiment ofthe process. Since increasing the reaction temperature increases theamount of sediment and coke precursors in the product, the temperatureincrease is selected to increase the amount of sediment and cokeprecursors in the upgraded product back to the original amount. The neteffect is an increase in conversion, with no increase in the sedimentload to downstream processing. Often, ebullated bed reaction zonetemperatures are increased in the range from 5° to 15° C. as the resultof using slurry catalyst in the reaction zone.

In one embodiment, the heavy oil dual catalyst processing systemincludes multiple ebullated bed reaction zones. Each reaction zone afterthe first receives at least a portion of the upgraded heavy oil productfrom the previous reaction zone. Any reaction zone that operates withaddition of the slurry catalyst will produce an upgraded productcontaining slurry catalyst. In one embodiment, this upgraded productwith slurry catalyst is passed to the next reaction zone in the series(if available).

Use of the multiple ebullated bed reaction zone system provides theopportunity to select any or all of the reaction zones for introductionof the slurry catalyst. In one embodiment, the slurry catalyst issupplied, in combination with a heavy oil feedstock, to the firstreaction zone. Reaction products, including converted heavy oil, alongwith at least a portion of the slurry catalyst, are passed to asubsequent reaction zone. In some such embodiments, the heavy oilfeedstock and the slurry catalyst are supplied to the first reactionzone only. In other embodiments, either additional heavy oil feedstock,slurry catalyst, or both, are also supplied to subsequent reactionzones. In one embodiment, a heavy oil feedstock is supplied to the firstreaction zone, without addition of a slurry catalyst. A slurry catalystis supplied to a subsequent reaction zone, either into a second reactionzone and/or into a reaction zone after the second (if any). In aspecific example, the heavy oil processing system includes threeebullated bed reaction zones. The second reaction zone is selected forintroduction of the slurry catalyst. Upgraded liquid product from thesecond reaction zone, that contains slurry catalyst, is passed to thethird reaction zone for continued upgrading. The slurry catalystprovides added benefit in the third reaction zone. Alternatively, theslurry catalyst is introduced solely to the third reaction zone in thethree reaction zone system. The slurry catalyst is particularlyeffective in reducing sediment and coke precursors in the upgradedproduct from the third reaction zone, since many of the most active cokeprecursors have been converted in the first and second reaction zones.Those coke precursors that are generated in the third reactor are moreeasily suppressed; the slurry catalyst provides a significantly largerbenefit in effectively removing those coke precursors.

Reference is now made to one embodiment of the hydroconversion reactionzone and the process for upgrading a heavy oil feedstock, as illustratedin FIG. 1. In FIG. 1, an ebullated bed heavy oil system comprises aheavy oil feed supply 12, a hydrogen supply 14, a slurry catalyst supply18, at least one feed preheater 46, a slurry catalyst conditioning unit48 and at least one feed inlet port 16. In an embodiment of the process,a reaction mixture comprising heavy oil feedstock 12, hydrogen 14, andslurry catalyst 18 is introduced into the ebullated bed reaction zone10. The ebullated bed reaction zone comprises a plenum chamber 24, anexpanded catalyst bed 20, and a disengagement zone 30. The plenumchamber is generally a lower region within the hydroconversion reactionzone and below the expanded catalyst bed or zone. The disengagement zoneis generally an upper region within the hydroconversion reaction zoneand above the expanded catalyst bed or zone. Hydrogen from hydrogensupply 14 is combined with heavy oil feedstock from heavy oil feedstocksupply 12 and heated in preheater 46. Slurry catalyst from slurrycatalyst supply 18 is combined with a carrier fluid in 48 to make acatalyst slurry, and mixed with the heated heavy oil feedstock andhydrogen blend, and the combination is provided to the ebullated bedreaction zone 10 through feed inlet port 16. Exemplary carrier fluidsthat are useful for forming the catalyst slurry include but are notlimited to hydrocarbons boiling in the heavy diesel range or the LVGOrange, including a boiling range from 400° to 700° F., or a full VGOrange boiling from 650-950° F., toluene, cycle oil, and even water for aslurry catalyst made from rework materials. In one embodiment, theslurry catalyst is presulfided.

In other embodiments (not shown), hydrogen from hydrogen supply 14 andheavy oil feed from heavy oil feed supply 12 are heated in separatepreheaters. Each heated stream is provided individually to the ebullatedbed reaction zone, or the heated streams are combined before beingprovided to the ebullated bed reaction zone 10. In one embodiment, theslurry catalyst is provided directly to the ebullated bed reaction zonethrough a separate slurry catalyst supply port, or the slurry catalystis blended with the heated hydrogen and/or the heated heavy oilfeedstock before being passed to the ebullated bed reaction zone. In allcases, the reaction mixture comprising the heated hydrogen, heated heavyoil, and slurry catalyst is blended with the hydrocarbonaceous liquidwithin the plenum chamber 24 of the ebullated bed reaction zone.

The reaction zone further includes an expanded catalyst zone 20comprising particulate catalyst that is maintained in an expanded orfluidized state against the force of gravity by upward movement offeedstock and gas through the ebullated bed reaction zone. The lower endof the expanded catalyst zone is defined by a distributor grid plate 22,which separates the expanded catalyst zone 20 from plenum chamber 24.The distributor grid plate distributes the hydrogen gas and upgradedheavy oil evenly across the reactor and prevents the particulatecatalyst from falling by the force of gravity into the plenum chamber.The top of the expanded catalyst zone is the height at which thedownward force of gravity begins to equal or exceed the uplifting forceof the upwardly moving upgraded heavy oil and gas through the ebullatedbed reaction zone as the particulate catalyst reaches a given level ofexpansion or separation. A disengagement zone 30 is separated fromexpanded catalyst zone 20 by interface 28. The design of thedisengagement zone 30 is based on separating the particulate catalystfrom the hydrocarbonaceous liquid. The design is also based on achievinga separation of gas and liquid so that the recirculated fluid is mostlyor completely liquid while the fluid exiting the reaction zone throughupgraded heavy oil withdrawal port 44 is the net liquid product and netproduct gas. Some of the hydrocarbonaceous liquid in the disengagementzone is recirculated back to the plenum chamber of the ebullated bedreaction zone, and some of the hydrocarbonaceous liquid, unreactedhydrogen and gaseous reaction products are removed through productwithdrawal port 44 from the disengagement zone for further processingoutside of the ebullated bed reaction zone. At least a portion of thehydrocarbonaceous liquid in the disengagement zone 30 is free ofparticulate catalyst.

Heavy hydrocarbonaceous liquid within the ebullated bed reaction zone iscontinuously recirculated from the disengagement zone 30 above theexpanded catalyst zone to the plenum chamber 24 below the expandedcatalyst zone by means of a recirculation conduit 36 disposed in thecenter of the ebullated bed reaction zone in communication with acirculation pump 34 disposed at the bottom of the ebullated bed reactionzone. At the top of the recirculation conduit 36 is a funnel-shapedrecirculation receiver 38 through which hydrocarbonaceous liquid isdrawn from the disengagement zone 30. The hydrocarbonaceous liquid drawninto the recirculation conduit is effectively, or completely, free ofparticulate catalyst, though the liquid contains a portion of the slurrycatalyst within the reaction zone. The upgraded heavy oil drawn downwardthrough the recirculation conduit enters the plenum chamber 24, where itis combined with the feedstock, hydrogen gas and slurry catalystentering the ebullated bed reaction zone through the input port 16. Thecombination then passes up through the distributor grid plate 22 andinto the expanded catalyst zone 20. Continuously circulating blendedheavy oil upward through the ebullated bed reaction zone advantageouslymaintains the particulate catalyst in the expanded catalyst zone in anexpanded or fluidized state within the expanded catalyst zone, minimizeschanneling, controls reaction rates, and keeps heat released by theexothermic hydrogenation reactions to a safe level.

Particulate catalyst is introduced into the ebullated bed reaction zonethrough a catalyst supply port 40 that passes through the top of theebullated bed reaction zone and into the expanded catalyst zone. Theparticulate catalyst that is introduced may be freshly made, it may bepartially deactivated catalyst that is recovered from an upgradingprocess, including the present process, or it may be a combination ofthe two, in any proportion. The particulate catalyst may be presulfided.Particulate catalyst is withdrawn from the expanded catalyst zonethrough a catalyst withdrawal port 42 that passes from a lower end ofthe expanded catalyst zone. Particulate catalyst that is withdrawn willgenerally include a range from catalytic qualities, including catalystthat has varying amounts of remaining activity and catalyst that iscompletely spent, with no remaining catalytic activity.

The slurry catalyst which is provided to the reaction zone is of a sizesuch that it is carried from the plenum chamber 24, through the expandedcatalyst zone 20 by the upflowing heavy oil and hydrogen and into thedisengagement zone 30. In effect, the catalyst is subjected to the sameamount of backmixing and recirculation as the heavy oil. Thus, theslurry catalyst is distributed throughout the hydrocarbonaceous liquidebullated bed reaction zone.

EXAMPLES

The following illustrative examples are intended to be non-limiting.

Example 1

A commercially available particulate catalyst from Advanced RefiningTechnology (ART) was provided as a particulate catalyst. The particulatecatalyst had a nominal cross-sectional diameter of 0.04 inch and alength of 0.1 inch to 0.4 inch, and contained 10% by weight molybdenumand 5% by weight nickel on an alumina base. Properties of theparticulate catalyst are listed in Table 1.

TABLE 1 Particulate Catalyst Rework Material Molybdenum content, wt. %10 wt. % 10 wt. % Nickel content, wt. %  5 wt. %  5 wt. % Surface Area,m2/g 288 m2/g 288 m2/g Pore Volume (by mercury 0.724 cm³/g 0.724 cm³/gporosimetry) Mesopore Volume (by mercury 0.162 cm³/g 0.162 cm³/gporosimetry in 100-300 A range)

Example 2

The particulate catalyst was dried for 1 hour under nitrogen at 400° F.A 1% dimethyldisulfide (DMDS) solution in heptane was injected for 1 hat 350° F. and at a pressure of 300 psi before ramping the temperatureto 450° F. Sulfiding was maintained for 14 hours at these conditionsbefore introducing a 6% DMDS solution and increasing pressure to 800 psifollowed by ramping to 650° F., where the temperature was maintained for2 hours.

Example 3

A sample of the particulate catalyst of Example 1 was ground, and thefraction that passed through a standard 650 mesh screen was collected asrework material. Properties of the rework material are listed in Table1.

An unsulfided catalyst slurry containing 92 grams of the rework materialand 7562 grams of the diluent blend having properties listed in Table 2was prepared.

Example 4 Comparative

A heavy oil feedstock, in the ratio 94.2 g/h vacuum residuum and 8.0 g/hdiluent (Table II), was provided to the ebullated bed pilot plant havinga total reactor volume of 372 cm³ at an average feed rate of 0.27volumes of feed per volumes of catalyst per hour, a temperature of 790°F. and a pressure of 2400 psig. The pilot plant employed the particulatecatalyst of Example 2. At these operating conditions, the conversion wasfound to be 70.8%, and the liquid product from the reaction zonecontained 3026 ppm sediment by the Shell Hot Filtration Test (VanKerkvoort, W. J. and Nieuwstad, A. J. J. Journal of the Inst. ofPetroleum (1951) 37, pp. 596-604).

TABLE 2 Vacuum Diluent Analysis Residuum Blend S, wt % 3.1 0.6 N, ppm6590 1382 C, % 85.2 84.1 H, % 10.5 11.0 MCR, % 17.5 7.4 Asphaltenes, wt.% 5.4 2.2 API 7.4 2.1 Density, g/cc 1.02 1.06 1000+ F., wt % 90 0.54 Ni,ppm 66 — V, ppm 214 —

Example 5

A heavy oil feedstock, in the ratio of 93.6 g per hour of the vacuumresiduum of Table I and the unsulfided slurry catalyst of Example 3 wasprovided to the ebullated bed pilot plant of Example 2 at an averagefeed ratio of 0.27 volumes of heavy oil feedstock per volume of catalystper hour and at a temperature of 790° F. and a pressure of 2400 psig. Atthese operating conditions, the conversion was found to be 69.9% and theliquid product from the reaction zone contained 1372 ppm sediment. Itwas observed that the use of the ground catalyst, while having littlemeasurable effect on the overall conversion, significantly decreased theamount of sediment that was formed.

Example 6

Example 5 was repeated at a temperature of 797° F. The conversion wasfound to be 74.2%, and the liquid product from the reaction zonecontained 1825 ppm sediment. As shown, the amount of sediment formedusing the ground slurry catalyst remained low, even at highertemperatures and higher amounts of conversion.

Example 7

Example 5 was repeated at 805° F. The conversion was found to be 77.9%,and the liquid product from the reaction zone contained 3058 ppmsediment. The reaction temperature was raised significantly with asubstantial increase in conversion, before sediment formation reachedthe level measured for the test without the slurry catalyst.

Example 8

A Mayan vacuum residuum feedstock having a boiling point range fromgreater than 1000° F. was contacted with a finely ground supportedcatalyst having a mean particle size of 45 microns and comprisingmolybdenum supported on an alumina base for 7 hours at 815° F. and 2500psi H₂ pressure. The results are tabulated in Table 3, showing theslurry catalyst was effective for upgrading the heavy oil residualmaterial.

TABLE 3 Ground Supported Catalyst Tested Catalyst Total catalyst Solids,% of VR Feed 6.4 Catalyst Dosage, ppm molybdenum/VR feed 1000 ProductAPI Gravity 28 Sulfur Conversion, % of Feed 95.4 VR conversion, % ofFeed 94.5 MCR conversion, % of Feed 89.6 Asphaltene conversion, % offeed 93.3

Example 9

In this example, a slurry catalyst with a Ni:Mo weight ratio of about10% was made. 33.12 g of ammonium heptamolybdate tetrahydrate((NH₄)₆Mo₇O₂₄) was dissolved in 100 g of water in a glass vessel fittedwith an overhead mechanical stirrer, and 14.1 g of concentrated ammoniasolution (28 wt. % NH₄OH in H₂O) was added. A solution of 8.1 g ofnickel sulfate hexahydrate (NiSO₄.6H₂O) in 32 g of water was added tothe first solution, all at ambient temperature, producing anemerald-green suspension. This suspension was heated to 70° C. underatmospheric pressure, and 101 g of ammonium sulfide ((NH₄)₂S) solutionin water (40-44 wt. %) was added slowly, over the course of 45 minutes.After that, the mixture was heated with stirring for an additional 60minutes. The volume of the reaction mixture was reduced in half on arotary evaporator. The resulting water-based catalyst precursor wastransformed to a final oil-based catalyst with VGO and hydrogen in apressure test autoclave.

Example 10

A duplicate of Example 5 is carried out, but instead of using a groundcatalyst for the slurry catalyst, the slurry catalyst of Example 9 isemployed. It is expected that the use of the slurry catalystsubstantially reduces the amount of sediment formed, and provides atleast equivalent if not better conversion for use in a system withoutthe addition of the slurry catalyst.

Example 11

A sample of the particulate catalyst of Example 1 was ground to anaverage particle size of 37 microns and collected as rework material,then mixed with a sufficient amount of VGO for a slurry catalyst(unsulfided) with a concentration of about 1.5 wt. % Mo in VGO.

Example 12

The slurry catalyst of Example 9 (Ni:Mo of 10 wt. %) was compared withthe unsulfided slurry catalyst of Example 11 in a heavy oil upgradereactor system using a VR feedstock having properties including:API—2.7; S—5.12 wt %; N—7900 ppm; C—83.24 wt %; H—9.53 wt %; Asph—25.7wt %; MCR—29.9 wt %; 1000 F+−95.7 wt %; Ni—141.9 ppm; and V—671.6 ppm.The system has 3 reactors in series, with the effluent stream from thefirst reactor comprising upgraded products, the slurry catalyst,hydrogen containing gas, and unconverted heavy oil feedstock being tothe second and then third reactor in series for further conversion. Theruns were made at about 815° F., 2500 psig H2 and residence time ofabout 7 hrs. Results are shown in Table 4, showing better performanceand with lower dosage of Mo catalyst when rework material is used toprepare the slurry catalyst.

TABLE 4 Slurry (Unsulfided) Slurry catalyst catalyst from CatalystTested/Results Example 9 rework - Example 11 Total catalyst Solids, % ofVR Feed 5.5 6.4 Catalyst Dosage, ppm Moly on VR 4000 1000 Product APIGravity 27.4 28 Sulfur Conversion, % of Feed 92.5 95.4 VR conversion, %of Feed 93.4 94.5 MCR conversion, % of Feed 87.4 89.6 Asphalteneconversion, % of feed 90.8 93.3

Example 13

A slurry catalyst similar to the slurry catalyst of Example 9 wasprepared from metal precursor feed, except that the amount of nickelsulfate precursor used was increased for a Ni:Mo ratio of about 23 wt.%. The slurry catalyst has a surface area of 157 m²/g, TPV of 0.358cc/g; PV (<100 A) of 0.1324 cc/g; PV (>100 A) of 0.2256 cc/g; and PV(25-1000 A) of 0.264 cc/g.

Example 14

A slurry catalyst was prepared according to the procedures listed inU.S. patent application Ser. No. ______ of the same filing date (DocketNo. T-8342), incorporated herein by reference. In the procedures, thecatalyst was prepared from water-soluble Mo metal precursor in solutionwith a pH of at least 4, with a water-soluble Ni salt as a promoter, fora Ni:Mo ratio of 23%. The water-based catalyst precursor was transformedin a VGO diluent forming a slurry catalyst The slurry catalyst hasexcellent porosimetry properties including a surface area of 221 m²/g;total pore volume of 0.836 cc/g, PV (<100 A) of 0.1892 cc/g, PV (>100 A)of 0.6468 cc/g; and PV (25-1000 A) of 0.71 cc/g.

Example 15

The slurry catalyst of Example 13 (high Ni:Mo of 23 wt. %) was comparedwith the slurry catalyst in Example 14 with improved porosimetryproperties. The catalysts were used to upgrade a heavy oil feedstock ina reactor system similar to Example 12. The results are shown in TableV, showing better performance for Example 14 at a substantially lowerdosage of catalyst.

TABLE V Slurry Slurry catalyst with catalyst improved porosimetryConversion Example 13 Example 14 Mo/VR concentration 3000 ppm 1500 ppmSulfur, % 80.93 81.17 Nitrogen, % 38.99 38.47 MCR, % 72.95 75.68 VR(1000 F.+), % 88.34 88.81 HVGO (800 F.+), % 75.08 76.29 VGO (650 F.+), %58.61 60.23 HDAs, % 66.43 76.38

Example 16

A duplicate of Example 5 is carried out, but instead of using a groundcatalyst, the slurry catalyst of Example 15 with improved porosimetry isemployed instead. It is expected that the use of the slurry catalystwith improved porosimetry properties (at a similar Mo/VR concentration)to substantially reduce the amount of sediment formed, and provideequivalent if not better conversion rates for use in a system withoutthe addition of the slurry catalyst.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the following specification andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by the present invention. It isnoted that, as used in this specification and the appended claims, thesingular forms “a,” “an,” and “the,” include plural references unlessexpressly and unequivocally limited to one referent. As used herein, theterm “include” and its grammatical variants are intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that can be substituted or added to thelisted items.

Features are described in terms of ranges, every integral or fractionalnumerical value falling between the end points of the ranges, includingthe end points of the ranges are fully within the scope of the statedrange.

Therefore, the present invention is well adapted to attain the ends andadvantages mentioned as well as those that are inherent therein. Theparticular embodiments disclosed above are illustrative only, as thepresent invention may be modified and practiced in different butequivalent manners apparent to those skilled in the art having thebenefit of the teachings herein. While numerous changes may be made bythose skilled in the art, such changes are encompassed within the spiritof this invention as defined by the appended claims. Furthermore, nolimitations are intended to the details of construction or design hereinshown, other than as described in the claims below. It is thereforeevident that the particular illustrative embodiments disclosed above maybe altered or modified and all such variations are considered within thescope and spirit of the present invention. The terms in the claims havetheir plain, ordinary meaning unless otherwise explicitly and clearlydefined by the patentee.

1. A dual catalyst system for use in a heavy oil upgrade process, thecatalyst system comprises: a particulate catalyst for use in an expandedcatalyst zone of an ebullated bed reactor to produce an upgraded heavyoil; a slurry catalyst prepared from a rework material obtained from aprocess of making hydroprocessing catalysts, wherein the rework materialhas an average particle size of less than 300 μm; wherein the slurrycatalyst upon being introduced into the ebullated bed reactor with aheavy oil feedstock is carried through the expanded catalyst zone andreduces formation of sediments and coke formation in the ebullated bedsystem.
 2. The dual catalyst system of claim 1, wherein the reworkmaterial has an average particle size of at least 1 μm.
 3. The dualcatalyst system of claim 2, wherein the rework material has an averageparticle size of 2-150 μm.
 4. The dual catalyst system of claim 1,wherein the rework material is obtained from a process of making anunsupported catalyst.
 5. The dual catalyst system of claim 1, whereinthe rework material is obtained from a process of making a supportedcatalyst.
 6. The dual catalyst system of claim 1, wherein the reworkmaterial is obtained by grinding a supported catalyst to an averageparticle size of less than 300 μm.
 7. The dual catalyst system of claim1, wherein the rework material is mixed with a diluent in an amount of 5to 40 wt. % of total weight of the diluent.
 8. The dual catalyst systemof claim 1, wherein the slurry catalyst prepared from rework materialhas an internal pore volume ranging from 0.5 cm³/g to 1.8 cm³/g.
 9. Thedual catalyst system of claim 1, wherein the slurry catalyst preparedfrom rework material has a polymodal pore size distribution with atleast a first mode having at least 80% pore sizes ranging from 5 to 2000Angstroms.
 10. The dual catalyst system of claim 1, wherein the slurrycatalyst prepared from rework material has at least 30% of pore sizes ofat least 100 Angstrom in diameter.
 11. The dual catalyst system of claim1, wherein the slurry catalyst prepared from rework material has a totalsurface area of at least 100 m²/g.
 12. The dual catalyst system of claim1, wherein the rework material is mixed with a diluent prior to beingintroduced into the ebullated bed reactor with the heavy oil feedstock.13. The dual catalyst system of claim 12, wherein the diluent isselected from water, VGO, cycle oil, gasoline, distillate, naphtha,light cycle oil, benzene, toluene, xylene, diesel oil, heptane, andmixtures thereof.
 14. The dual catalyst system of claim 1, wherein therework material upon being introduced into the ebullated bed reactorwith a heavy oil feedstock, the heavy oil feedstock releases asufficient amount of at least a sulfiding agent to sulfide the reworkmaterial in-situ to form the active slurry catalyst.
 15. The dualcatalyst system of claim 1, wherein the rework material is obtained froma process of making a supported catalyst comprising a porous refractorybase.
 16. A dual catalyst system for use in a heavy oil upgrade process,the catalyst system comprises: a particulate catalyst for use in anexpanded catalyst zone of an ebullated bed reactor to produce anupgraded heavy oil; catalyst fines comprising at least one of a metaloxide, a metal hydroxide, a metal sulfide and combinations thereof,affixed onto a carrier comprising one or more of alumina, iron oxide,silica, magnesia, titania, zeolite, silica-aluminate, carbon,phosphorous, and combinations thereof, wherein the catalyst fines havean average particle size of less than 300 μm; wherein the catalyst finesupon being introduced into the ebullated bed reactor with a heavy oilfeedstock is sulfided in-situ forming an active slurry catalyst which iscarried through the expanded catalyst zone and reduces formation ofsediments and coke formation in the ebullated bed system.
 17. The dualcatalyst system of claim 16, wherein the catalyst fines are obtainedfrom a process of making a supported catalyst.
 18. The dual catalystsystem of claim 16, wherein the catalyst fines are obtained by grindinga supported catalyst to an average particle size of less than 300 μm.19. The dual catalyst system of claim 16, wherein the catalyst fines aremixed with a diluent prior to being introduced into the ebullatedreactor system with the heavy oil feedstock.
 20. The dual catalystsystem of claim 19, wherein the diluent is selected from water, VGO,cycle oil, gasoline, distillate, naphtha, light cycle oil, benzene,diesel oil, heptane, toluene, xylene, and mixtures thereof.
 21. The dualcatalyst system of claim 16, wherein the slurry catalyst formed from thecatalyst fines has an internal pore volume ranging from 0.5 cm³/g to 1.8cm³/g.
 22. The dual catalyst system of claim 16, wherein the slurrycatalyst formed from the catalyst fines has a polymodal pore sizedistribution with at least a first mode having at least 80% pore sizesranging from 5 to 2000 Angstroms.
 23. The dual catalyst system of claim16, wherein the slurry catalyst formed from the catalyst fines has atleast 30% of pore sizes of at least 100 Angstrom in diameter.
 24. Thedual catalyst system of claim 16, wherein the slurry catalyst formedfrom the catalyst fines has a total surface area of at least 100 m²/g.25. The dual catalyst system of claim 16, wherein catalyst finescomprises at least a metal oxide or at least a metal hydroxide of atleast a Primary metal selected from Group VIB metals, Group VIII metals,and combinations thereof.
 25. A method of upgrading a pre-existingebullated bed hydroprocessing system in order to reduce formation ofcoke and/or sediment, comprising: operating a pre-existing ebullated bedhydroprocessing system comprising one or more ebullated bed reactors,each of which comprises a liquid hydrocarbon phase, a solid phasecomprised of an expanded bed of a porous supported catalyst, a gaseousphase comprised of hydrogen gas, and catalyst free zones above and belowthe expanded bed of the porous supported catalyst; providing catalystfines at a rate of about 5 ppm to about 1000 ppm catalyst fines byweight of the heavy oil feedstock, the catalyst fines are obtained froma process of making hydroprocessing catalysts, wherein the catalystfines have an average particle size of less than 300 μm; introducing theheavy oil feedstock and the catalyst fines into at least one ebullatedbed reactor of the pre-existing ebullated bed hydroprocessing system;and operating the ebullated bed hydroprocessing system to form ahydroprocessed material; wherein the catalyst fines upon being sulfidedin-situ upon contact with the heavy oil feedstock under hydroprocessingconditions in the ebullated bed reactor, becoming catalytically activethereby reducing formation of coke and/or sediment in the upgradedebullated bed hydroprocessing system compared to a pre-existingebullated bed hydroprocessing system without the addition of thecatalyst fines.
 26. The method of claim 25, further comprising: mixingthe catalyst fines with a diluent generating a slurry catalyst andmixing the slurry catalyst with the heavy oil feedstock prior tointroducing the heavy oil feedstock and the catalyst fines into at leastone ebullated bed reactor.
 27. The method of claim 26, wherein thecatalyst fines are mixed with a diluent selected from the group of fromwater, VGO, cycle oil, gasoline, distillate, naphtha, light cycle oil,benzene, diesel oil, heptane, toluene, xylene, and mixtures thereof. 28.The method of claim 25, wherein the catalyst fines provided at a rate ofabout 10 ppm to about 500 ppm catalyst fines by weight of the heavy oilfeedstock.
 29. The method of claim 25, wherein the catalyst finesreduces the formation of coke and/or sediment in the upgraded ebullatedbed hydroprocessing system of at least 10% compared to a pre-existingebullated bed hydroprocessing system without the addition of thecatalyst fines.
 30. The method of claim 25, wherein the catalyst finesreduces the formation of coke and/or sediment in the upgraded ebullatedbed hydroprocessing system of at least 15% compared to a pre-existingebullated bed hydroprocessing system without the addition of thecatalyst fines.
 31. The method of claim 25, wherein providing catalystfines obtained from a process of making hydroprocessing catalystscomprises grinding a supported catalyst for use in hydroprocessing to apowdered material having an average particle size of less than 300 μm.32. The method of claim 25, wherein providing catalyst fines obtainedfrom a process of making hydroprocessing catalysts comprises grinding aself-supported catalyst for use in hydroprocessing to a powderedmaterial having an average particle size of less than 300 μm.
 33. Themethod of claim 25, wherein providing catalyst fines obtained from aprocess of making hydroprocessing catalysts comprises: a) grinding asupport base material to an average particle size of less than 300 μm;b) impregnating the reduced particle sized support base material with atleast a metal precursor; c) drying the impregnated support basematerial; and d) grinding the impregnated support base material to aparticle size of less than 300 μm.